Top portion of a bottle cap



FIG. 1 is a front perspective view of a bottle cap incorporating our new design of a top portion of a bottle cap;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIGS. 4 and 5 are side elevational views thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings depict environmental subject matter and form no part of the claimed design. 

The ornamental design for a top portion of a bottle cap, as shown and described. 